Deepwreck

I have done dives in 39 degree water with a current. I use a Classic, and I try not to go beyond 3 to 4 hours on the sorb. With that say Ill open myself up for some flaming.
On one cold A-- dive(water around 41 degrees all the way up) the current at the surface was just cooking, and it was all I could do to get to the down line, and stay on that line. My heart felt like it was going to explode, and my lungs, well my lungs were burning. Once down to around 70 or 80 feet the current let off and my hand over hand desent with full kicking to aid ended and I had a chance to catch my breath. The Wreck was 200 feet and bottom time was about 25 min. The ascent went fine other than having to hang on for dear life. This was the Second dive of the day and all total with the two dives I had just over 5hrs on the scubber. (not recomembed) Both dives were in the same water with depths of 200' to 220'. The water was scheduled to be around 70 degrees for deco above 40', but all that warm water was blown south, and all be got was 41 degrees from surface to depth.
So I would have to say that Im happy with the way my unit works and functions under workload, and cold water. However you may want to talk to others who have overworked there units, and under what conditions they overworked them. I know of some who have overbreathed the units, and its not pretty or fun. So one must always take care to watch just how hard we are breathing.
Just my 2cents.